<template>
	<view class="s-navigation-bar"
		:class="{ 's-bar-line': opacity > 0.85 && splitLine, 's-navbar-fixed': isFixed, 's-backdrop__filter': backdropFilter && dropDownOpacity > 0  }"
		:style="{ height: height + 'px', backgroundColor: `rgba(${background},${opacity})`, opacity: dropDownOpacity, zIndex: isFixed ? zIndex : 'auto' }">
		<view class="s-status-bar" :style="{ height: statusBarHeight + 'px' }" v-if="isImmersive"></view>
		<view class="s-navigation_bar-title"
			:style="{ opacity: transparent || opacity >= maxOpacity ? 1 : opacity, color: color, paddingTop: top - statusBarHeight + 'px' }"
			v-if="title && !isCustom">
			{{ title }}
		</view>
		<slot />
	</view>
</template>

<script>
	export default {
		name: 'sNavigationBar',
		emits: ['init', 'change'],
		props: {
			//NavigationBar标题
			title: {
				type: String,
				default: ''
			},
			//NavigationBar标题颜色
			color: {
				type: String,
				default: '#333'
			},
			//NavigationBar背景颜色,不支持rgb
			backgroundColor: {
				type: String,
				default: '#fff'
			},
			//是否需要分割线
			splitLine: {
				type: Boolean,
				default: false
			},
			//是否设置不透明度
			isOpacity: {
				type: Boolean,
				default: true
			},
			//不透明度最大值 0-1
			maxOpacity: {
				type: [Number, String],
				default: 1
			},
			//背景透明 【设置该属性，则背景透明，只出现内容，isOpacity和maxOpacity失效】
			transparent: {
				type: Boolean,
				default: false
			},
			//滚动条滚动距离
			scrollTop: {
				type: [Number, String],
				default: 0
			},
			/*
				 isOpacity 为true时生效
				 opacity=scrollTop /windowWidth * scrollRatio
				*/
			scrollRatio: {
				type: [Number, String],
				default: 0.3
			},
			//是否自定义header内容
			isCustom: {
				type: Boolean,
				default: false
			},
			//是否沉浸式
			isImmersive: {
				type: Boolean,
				default: true
			},
			isFixed: {
				type: Boolean,
				default: true
			},
			//是否开启高斯模糊效果[仅在支持的浏览器有效果]
			backdropFilter: {
				type: Boolean,
				default: false
			},
			//下拉隐藏NavigationBar，主要针对有回弹效果ios端
			dropDownHide: {
				type: Boolean,
				default: false
			},
			//z-index设置
			zIndex: {
				type: [Number, String],
				default: 9998
			}
		},
		watch: {
			scrollTop(newValue, oldValue) {
				if (this.isOpacity && !this.transparent) {
					this.opacityChange();
				}
			},
			backgroundColor(val) {
				if (val) {
					this.background = this.hexToRgb(val);
				}
			}
		},
		data() {
			return {
				width: 375, //header宽度
				left: 375, //小程序端 左侧距胶囊按钮距离
				height: 44, //header高度
				top: 0,
				scrollH: 1, //滚动总高度,计算opacity
				opacity: 1, //0-1
				statusBarHeight: 0, //状态栏高度
				background: '255,255,255', //header背景色
				dropDownOpacity: 1
			};
		},
		created() {
			this.dropDownOpacity = this.backdropFilter && 0;
			this.opacity = this.isOpacity || this.transparent ? 0 : this.maxOpacity;
			this.background = this.hexToRgb(this.backgroundColor);
			let obj = {};
			// #ifdef MP-WEIXIN
			obj = wx.getMenuButtonBoundingClientRect();
			// #endif
			// #ifdef MP-BAIDU
			obj = swan.getMenuButtonBoundingClientRect();
			// #endif
			// #ifdef MP-ALIPAY
			my.hideAddToDesktopMenu();
			// #endif
			uni.getSystemInfo({
				success: res => {
					this.statusBarHeight = res.statusBarHeight;
					this.width = res.windowWidth;
					this.left = obj.left || res.windowWidth;
					if (this.isImmersive) {
						this.height = obj.top ? obj.top + obj.height + 8 : res.statusBarHeight + 44;
					}
					this.scrollH = res.windowWidth * this.scrollRatio;
					this.top = obj.top ? obj.top + (obj.height - 32) / 2 : res.statusBarHeight + 6;
					this.$emit('init', {
						width: this.width,
						height: this.height,
						left: this.left,
						top: this.top,
						statusBarHeight: this.statusBarHeight,
						opacity: this.opacity,
						windowHeight: res.windowHeight
					});
				}
			});
		},
		methods: {
			hexToRgb(hex) {
				let rgb = '255,255,255';
				if (hex && ~hex.indexOf('#')) {
					if (hex.length === 4) {
						let text = hex.substring(1, 4);
						hex = '#' + text + text;
					}
					let result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
					if (result) {
						rgb = `${parseInt(result[1], 16)},${parseInt(result[2], 16)},${parseInt(result[3], 16)}`;
					}
				}
				return rgb;
			},
			opacityChange() {
				if (this.dropDownHide) {
					if (this.scrollTop < 0) {
						if (this.dropDownOpacity > 0) {
							this.dropDownOpacity = 1 - Math.abs(this.scrollTop) / 30;
						}
					} else {
						this.dropDownOpacity = 1;
					}
				}

				let scroll = this.scrollTop <= 1 ? 0 : this.scrollTop;
				let opacity = scroll / this.scrollH;
				if ((this.opacity >= this.maxOpacity && opacity >= this.maxOpacity) || (this.opacity == 0 && opacity ==
					0)) {
					return;
				}
				this.opacity = opacity > this.maxOpacity ? this.maxOpacity : opacity;
				if (this.backdropFilter) {
					this.dropDownOpacity = this.opacity >= this.maxOpacity ? 1 : this.opacity;
				}
				this.$emit('change', {
					opacity: this.opacity
				});
			}
		}
	};
</script>

<style scoped>
	.s-navigation-bar {
		width: 100%;
		transition: opacity 0.4s;
	}

	.s-backdrop__filter {
		/* Safari for macOS & iOS */
		-webkit-backdrop-filter: blur(15px);
		/* Google Chrome */
		backdrop-filter: blur(15px);
	}

	.s-navbar-fixed {
		position: fixed;
		left: 0;
		top: 0;
	}

	.s-status-bar {
		width: 100%;
	}

	.s-navigation_bar-title {
		width: 100%;
		font-size: 17px;
		line-height: 17px;
		/* #ifndef APP-PLUS */
		font-weight: 500;
		/* #endif */
		height: 32px;
		display: flex;
		align-items: center;
		justify-content: center;
	}

	.s-bar-line::after {
		content: '';
		position: absolute;
		border-bottom: 1rpx solid #eaeef1;
		-webkit-transform: scaleY(0.5);
		transform: scaleY(0.5);
		bottom: 0;
		right: 0;
		left: 0;
	}
</style>
